Grafts that aid in the healing of damaged bone are a relatively old technology that have undergone substantial growth in light of recent advances in medicine and biology. Improved understanding of osteoinductive and osteoconductive properties of certain materials has enabled the design of implants of ever-increasing efficacy. Recent examples include U.S. Pat. No. 7,045,141 to Merboth et al., entitled “Allograft Bone Composition Having a Gelatin Binder”; U.S. Pat. No. 6,808,585 to Boyce et al., entitled “Osteogenic Implant Derived From Bone”; U.S. Pat. No. 6,548,080 to Gertzman et al., entitled “Method for Partially Demineralized Cortical Bone Constructs”; and U.S. Pat. No. 6,776,800 to Boyer, I I et al., entitled “Implants Formed with Demineralized Bone,” all of which are incorporated herein by reference. Absorbable Collagen Sponge (“ACS”), by Integta LifeSciences Corporation (Plainsboro, N.J.), and Mastergraft© Matrix, by Medtronic Sofamor Danek (Memphis, Tenn.), are specific examples of grafts currently available on the market.
Many of these implants are easily contourable, but do not provide any structural support at the implant site. Structural support ranges from the ability to resist the tendency for compression of the graft by local tissues (space maintenance), to the ability to be weight bearing. There exist numerous situations in which it is desirable to have an implant that both aids in the re-growth of the bone at the implant site while also providing structural support, which are so-called structural implants. A drawback of structural implants is that the mechanical strength that they impart necessarily means that they tend to be difficult to contour to the geometry of the implant site. Additionally, structural implants tend to be less readily remodeled than their non-structural counterparts.
It is therefore desirable to provide an osteoimplant that provides structural (space maintaining and/or weight bearing) capabilities, yet which may be readily contourable, and which provides superior osteoinductive, osteoconductive and re-absorption properties.